help ldap_sasl_bind_s failed (-1)

HiI have configured the openldap multimaster based on this guide: https://kifarunix.com/setup-openldap-master-master-replication-on-centos-8/%... the replication between two servers doesn't work. and I get these errors: on server1: slap_client_connect: URI=ldaps://ldapmaster02.kifarunix-demo.com DN="cn=admin,dc=ldapmaster,dc=kifarunix-demo,dc=com" ldap_sasl_bind_s failed (-1)

on server 2:slap_client_connect: URI=ldaps://ldapmaster01.kifarunix-demo.com DN="cn=admin,dc=ldapmaster,dc=kifarunix-demo,dc=com" ldap_sasl_bind_s failed (-1). I didn't receive any reply from the article writer.what is wrong in the guide? Regards